This image actually started as a random sketch. I had decided I just wanted to draw something purple, and since people are one of my favourite painting subjects, I decided to paint a girl with purple as the colour scheme. After leaving the sketch alone for some time, I decided to work on it some more.
I began this image with a plain background in Photoshop onto which I splashed on some colours and overlaid a texture (Fig.01). This was because I don't like working on plain-looking backgrounds. Adding a texture and some varying colour keeps me interested in an image and also helps me to achieve the desired mood with a bit more ease.
I then created a new layer and started the sketch. I blocked in the colours with a large hard round brush and then roughly added detail with a smaller size of the same blocking brush (Fig.02). I also created a new layer for the hair, and roughly painted it in. It was at this point that I decided to leave it alone and forgot about it for a while.
Coming back to it later, I decided to improve upon it, as I liked the direction it was taking. I further detailed her face and shoulder, using a small hard round brush and soft round brush to smooth it out as I went along. I also worked a little more on the hair and robe, added some makeup, and decided that I wanted her to have purplish-blue eyes (Fig.03).